Mechanical instrument.



PATENTED JULY 28, 1903.

L. FREGHETTE.

MECHANICAL INSTRUMENT.

APPLICATION FILED OUT. 17, 1902.

2 SHEETSSHEET 1.

N0 MODEL.

WITNESSES.-

PATENTED JULY 28, 1903.

L. PRECHBTTE. MECHANICAL INSTRUMENT.

APPLIOATIOK FILED 0013.17. 1902.

no MODEL,

2 SHEETS-SHEET 2.

UNITED STATES Patented July 28, 1903.

PATENT OFFICE.

LEOPOLD FRECHETTE, OF HOLYOKE, MASSACHUSETTS, ASSIGNOR TO HERMINE FRECHETTE, OF HOLYOKE, MASSACHUSETTS.

MECHANICAL INSTRUMENT.

SPECIFICATION formingpart of Letters Patent No. 734,694, dated July 28, 1903. Application filed October 17, 1902. Serial No. 127,644. (No model.)

I To all whmn it may concern:

Be it known that I, LEOPOLD FRECHETTE, a citizen of the United States, residing at Holyoke, in the county of Hampden and State of Massachusetts, have invented certain new and useful lmprovementsin Mechanical Instruments; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the letters and figures of reference marked thereon, which form a part of. this specification.

My invention relates to mechanical instruments, but more particularly to bevels, and has for its object to provide a device of this class which is designed to be used by carpenters or builders.

A further object of my invention is to provide an instrument which will give the length and cuts of a brace or rafter, which brace or rafter is the hypotenuse of a right-angled triangle the lengths of the side and base of which are known.

A further object of myinvention is to provide an instrument which will give the length and cut of a bevel for mitering molding, &c.

A further object of my' invention is to provide an instrument which. is particularly adapted to be used by stone-masons in building arches, dzc.

A further object of my invention is to provide an instrument which will give the four cuts of a panel or the like which is a parallelogram, but not righaangled.

With all these objects in view my inven-' .tion consists-in the novel arrangement of my instrument or square, but more particularly in the relative arrangement of the sliding arm or member with the pivoted members of the square.

'My invention also consists in certain other novel features, which will befirst fully described, and afterward specifically pointed out in the appended claims. 7

Referring to the accompanying drawings, Figure 1 is a plan View of my invention. Fig. 2 is a cross-section taken on the lines 2 2 of Fig. 1. Fig. 3 is a fragmentary perspective view of the under side of the sliding arm or lengths and cuts of rafters and braces for buildings' Fig. 6 shows manner of determining the cut or bevel for molding or for ascertaining the length and cuts of timber for braces, rafters, &c. Fig. 7 is a view showing the manner of ascertaining the angles for the contiguous faces of the stone in an arch, 850.

Like characters of reference indicate the same parts throughout the several figures, in whieh- 1 indicates my instrument, having the central leg or member 2, which is provided with a groove 3 its entire length.

4 indicates the main scaled arm, pivoted to the central leg at 5. Pivoted at 6 to said main arm 4 is a member 7, which is of a length equal to the distance between the pivots 5and 6. Said member 7 is pivoted to the sliding set-pin 8, as shown in Fig. 2. Said pin is provided with an enlarged head 9, which operates in the groove 3 of the central leg 2 and is provided with a threaded thumbnut 10. Pivoted also to said pin 8 between the member 7 and the central leg 2 is the member 11 of an equal length with member 7, and pivoted to said member 11 at 12 is the member 13 of the same length, which member is pivoted to the central leg at 5.

r 14 indicates the sliding scaled arm which operates on the central leg 2 and which is provided with a set-screw 15.

Having thus described the several parts of my invention, its operation is as follows: The central leg 2, main arm 4, and sliding .arm 14 are scaled, preferably, one inch to the foot, but any system of scaling may be used without in any way departing from the spirit of my invention. As before stated, my invention consists particularly in the relative" arrangement of the said sliding arm to the other scaledmembers of the square, and throughout the operations which will now be described I wish to particularly direct attention to the same.

Referring now to Fig. 4, Aindicates-a panel, the opposite sides of which are parallel and the opposite angles equal, but not right angles. It is therefore desired to ascertain the ICO cuts or bevels at said angles in order to properly miter the molding. The square is laid, as shown, with the members 7 and 11 parallel with the sides of the panel. A line then drawn on the central leg 2 indicates the required out or bevel and the length of same. Thus the miters for the two corners are obtained; but the two remaining bevels would be unknown were it not for the sliding arm 14; but, as is plainly seen, a line drawn on said sliding arm indicates the cut or bevel for the remaining miters, and this, too, without moving the square. All fourcuts are therefore indicated at one operation of the square.

Refer now to Fig. 5, in which B, B B and B represent rafters the lengths and bevels of which are unknown, although the timber O is twenty-four feet or twelve feet'from D to E. Supposing, therefore, that it is intended to pitch the rafter B twelve feet, the lengths and bevels of which are unknown. In this instance the sliding arm 14 is placed on the twelfth inch of the scale on the central leg, as shown in Fig. 6, and the main scaled arm 4 is moved to the twelfth inch on the sliding arm corresponding to the twelve feet which is half the length of the timber C. We therefore find the length of the rafter B, which is the hypotenuse of a triangle having a base and side of twelve feet. The length of the rafter is therefore seventeen feet, as indicated on the main scaled arm 4:, as shown in Fig. 6. It is also seen that besides giving the length of the rafter both bevels are indicated, the lower one by the sliding arm and the upper one by the central leg. The length of the rafters B, B and B with pitches of three feet three inches, six feet, and nine feet, respectively, are ascertained in like manner, the bevels or cuts changing with the lengths of the rafters, all of which are indicated at one operation. In like manner it maybe required to ascertain the length and cuts of a brace F, being two feet nine inches to the left of the upright G and five feet nine inches on said upright. In this instance the sliding arm is placed on the central leg at a point corresponding to five feetnine inches, and the main scaled arm is set on the sliding arm at a point corresponding to two feet nine inches. Thus the length of said brace F is equal to the hypotenuse of atriangle with a base of two feet nine inches and side of five feet nine inches,

which hypotenuse or brace is six feet four and three-fourthsiriches. Both cuts or length of said brace are also indicated by the sliding arm and central leg. The brace H and cuts are found in like manner.

Referring now to Fig. 7, I indicate a stone arch, and it is desired to determine the exact angle of cutting the stone in order to have them with even joints. In this instance the square is placed as shown and the sliding arm moved on a line with the diagonal of the parallelogram, which is the line required and shown dotted in Fig. 7.

Having thus described my invention, or rather some of the operations of my square, it is obvious that the same may be employed in numerous other instances, the foregoing, however, being deemed sufficient to clearly illustrate the utility and operation of my invention.

Regarding the construction of the square, I do not wish to be understood as limiting myself to that specifically described, as it is obvious that various slight changes may be made therein which would fall within the limit and scope of my invention, and I consider myself clearly entitled to all such changes and modifications. 1

What I claim as my invention, and desire to secure by Letters Patent of the United States, is- I v 1 1. The combination with a central scaled leg, of a main scaled arm pivoted thereto, a member pivoted to said scaled arm, means forslidably securing said member to said central scaled arm and a sliding arm carried on said central scaled leg, substantially and for the purposes set forth.

2. The combination with a central scaled leg provided with a longitudinal groove therein, of a main scaled arm pivoted thereto, a member pivoted to said scaled arm a sliding set-pin carried in said groove in said central arm and pivoting said member to said central arm, a sliding arm carried on said central leg,-substantially as described, and for the purpose set forth.

In testimony whereof I affix my signature in presence of two witnesses.

LEOPOLD FRECHETTE.

Witnesses:

HILAIRE JACQUES, J r., THOMAS D. OBRIEN. 

